Tube-rolling method and apparatus



May 12, 1925. 1,537,206

M. u. WIKSTROM TUBE ROLLING METHOD AND APPARATUS 7 Filed March 17, 19225 2 Sheets-Sheet 1 FIG. 1

INVEN'TZFII(Ala/cgZ M JmL/QMM May 12, 1925. 1,537,206

r M. u. WIKSTROM TUBE ROLLING METHOD AND APPARATUS Filed Marqh 1'7, 1923 2 Sheets-Sheet 2 19 A v 7 M L 3M f z mggm Patented May 12, 1925.

UNITED STATES MALCOLM U. WIKSTROM, OF PITTSBURGH, PENNSYLVANIA.

TUBE-ROLLING METHOD AND APPARATUS.

Application filed March 17, 1923. Serial No. 625,771.

To all whom it may concern:

Be it known that I, MALCOLM U. VVIK- STROM, a citizen of the United States, and resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Tube-Rolling Methods and Apparatus; and I do hereby declare the following to be a full. clear, and exact description thereof.

My invention relates to a method of and apparatus for making seamless tubing.

I-Ieretofore in the manufacture of scamless tubing where a two-high mill is employed, it has been customary to have a stationary mandrel-rod at the rear of the rolls, said mandrel-rod having a projection at its outer end adapted to enter a correspondingly shaped seat or recess formed in a conical plug over which the tube is rolled, said plug being located in the pass of the rolls during the rolling operation. The front or tapering end of the plug has a projection to be grasped by tongs in the hands of a workman who adjusts the plug in position on the mandrel-bar and removes it therefrom after the tube'has been passed through the rolls. In a mill of this character, the upper-roll is adapted to be raised and lowered, so that when the tube had been passed through the rolls and over the plug on to the mandrel-bar, by lifting the upper roll the tube may be fed back through the pass in the rolls into position to be again passed through the rolls after the upperroll has been lowered. The plug is adjusted in position by the tongs in the manner above referred to each time a tube is passed through the rolls, and has to be removed before the return of the tube, and as these plugs are often heavy in the making of tubes of large diameters the lifting of the plugs and inserting and withdrawing them from position is a laborious task.

By my invention I propose to dispense with this manual labor in the handling of the plugs, and I accomplish this by employing a spherical plug instead of a conical plug, and by the use of such spherical plug I am enabled to provide for the automatic delivery of the plug in position for the rolling operation, and likewise its automatic discharge from the roll-pass when the tube is returned, the result being that the plugs are not manually handled, and consequently the labor and expense isgreatly reduced and the output increased, while at the same time by the employment of a spherical plug the friction in rolling is reduced, and the spherical shape of the plug permits of any part of its surface being used, so that all of its surface is liable, in time, to be brought into play and the wear is not confined to certain restricted areas, as in the case of the conical plug.

' In the accompanying drawings, Fig. 1 1s a longitudinal section of the apparatus for carrying out my invention, the illustration being more or less diagrammatic, the spherical plug being shown in position when the rolling of the tube is taking place; Fig. 2 is a like view after the tube has been rolled and is being returned by the return-rolls, the spherical plug being indicated as being pushed back out of position to descend the chute; Fig. 3 is a like View showing the spherical plug being delivered to the rolls; Fig. 4: is a front View of the rolls showing the manner of conducting the spherical plugs from the rolls to the chute and thence to be carried up to be again delivered to the delivery device; Fig. 5 is a detail of the conveyor for lifting the spherical plugs taken on the line 5-5, Fig. 4; and Fig. 6 is an enlarged portion of the rolls showing the spherical ball in position when the tube is being rolled.

In the drawings the upper and lower rolls are indicated by the numerals 2 and 3, it being understood that the upper roll is preferably adapted to be raised, as in most mills of this character, to allow for the return of the tube, said rolls rotating in opposite directions, as indicated by the arrows. In the rear of the rolls 2 and 3 are the return-rolls 4 and 5, by means of which the tube is returned to the front of the rolls, as will more fully hereinafter appear.

A mandrel-bar 6 is suitably supported in the rear of the rolls, said mandrel-bar having the head 7 with the conical recess8 formed therein, and this head 7 is preferably removably attached to said mandrelbar, so that when it wears out a new one may be substituted, and for this reason said head has the stud 9 which enters a correspondingly shaped seat 10 in the end of the mandrel-bar.

On the feeding side of the rolls is the trough 11 to support the tube, and at the forward end of said trough is the guide 12 for delivering the spherical plugs 13 to the rolls, said guide also serving as a support for the plug when said plug is pushed back from the roll-pass, after the tube has been rolled, as clearly indicated in Fig. 2. lhe guide 12 is preferably slightly inclined toward the roll-pass, as indicated in the drawings so that the plug naturally rolls toward the roll-pass when delivered to said guide, as indicated in Fig. 3.

The trough 11 is provided with the opening 14 communicating with the chute 15 which is connected at its lower end with the transverse trough 16 which is slightly inclined to deliver the plugs to the conveyor 17 at the outer end of said trough. lVater may be employed in the trough if desired' The conveyor 17 may be of any suitable construction. the one shown comprising a chain belt 18 with flights 19 carried at intervals thereon, said chain being mounted on sprockets 20 and driven in any suitable manner, so that each time a flight comes around in the bottom of the trough 16 it will pick up a ball and carry it up the guide 21 to deliver it into the transverse trough 22 which is slightly inclined toward the rolls.

At the inner end of the trough 22 is the tiltable delivering device 23 which is mounted on the rock-shaft 24 journaled in the frame 25. The outer end of the rock-shaft 24 has the handle 26. The tilting member 23 has the stop-plate 27 which acts as a stop when the member 23 is tilted to prevent a ball from rolling from the trough 22, so that only one plug at a time is delivered to the guide 12.

In the operation of my invention the handle 26 is moved to rock the shaft 24, so as to deliver a spherical plug on to the guide 12, as indicated in Fig. 3. As the guide is slightly inclined the plug will roll toward the pass of the rolls, and is in position to be picked up by the pierced blank 28 from which the tube is to be formed. In this way the spherical plug is advanced into position in the pass of the rolls and is received in the conical recess 8 of the head 7 of the mandrelbar 6, as shown in Fig. 6. The blank 28 is reduced by passing over the spherical plug with the rolls acting upon the walls of the blank, so that the thickness of the walls is reduced and the blank elongated. After the blank has been passed entirely through the rolls, the upper-roll 2 is raised slightly and the return-rolls 1 and 5 are brought into play to return the tube back into the trough. 11 for another rolling operation. As the tube returns, as shown in Fig. 2, it forces the spherical plug from its position between the rolls and advances it on to the guide 12, so that when said plug reaches the opening 1 1 it will pass down the chute 15 into the trough 16, whence it will in turn pass to the conveyer 17 to be lifted into the trough 22.

In the rolling of a seamless tube in a mill of this character, it is customary to gradually increase the inside diameter of the tube by increasing the size of the plug at each pass through the rolls. That is, if it takes three passes to bring the tube to proper length and diameter, in the first pass the tube will be rolled over a plug of a certain diameter, and on the next pass it will be arranged to have aplug of slightly larger diameter delivered to the guide 12, and on the third pass a plug of still larger diameter, and accordingly said plugs are arranged in the trough 22 to come up in the order indicated to be delivered in succession by the tilting member 23 on to the guide 12.

By the use of a spherical plug I provide a plug which is readily handled automatically, as no particular surfare of the plug is required to contact with the inner walls of the tube, and consequently there is also an even wear on all points of the spherical plug, as the surface presented to the tubing is always changed, whereas in a conical plug the surface area in contact with the tube is always the same. Furthermore there is less friction by the employment of the spherical plug, as there is less surface in contact with the tube during the rolling operation.

Another great advantage is that the plugs have an opportunity to cool, without the use of water, by the time they come around again in position to be delivered to the rolls, and it is not necessary to use water for cooling, which Water tends to strain the metal and cause cracks which destroy the usefulness of the plugs.

\Vhat I claim is:

1. The method of making seamless tubing consisting in passing the tubular blank through a pass between rolls and over a spherical plug holding the plug centered in position with respect to the pass of the rolls.

2. The method of making seamless tubing consisting in supporting a spherical plug in position in front of the roll-pass and moving the plug into centered position in respect to the roll-pass by the advancing tubular blank and passing the said blank through the rolls over said plug.

3. In apparatus for making seamless tubing, the combination with rolls, of a mandrel-bar, and a spherical plug engaging said mandrel-bar in centered relation with respect to the pass of the rolls.

1. In apparatus for making seamless tubing, the combination with the rolls, of a mandrel-bar, a spherical plug adapted to engage said mandrel-bar and means for contering said plug with respect to the pass of the rolls, and a guide in front of said rolls for said spherical plug, whereby the advancing tube will move said plug into engagement with said mandrel-bar.

5. In apparatus for making seamless tubing, the combination with the rolls, of a mandrel-bar, a plug adapted to engage said mandrel-bar in the pass of the rolls, a guide in front of said rolls and means for deliver; ing the plug to said guide,- whereby said plug is advanced by the tube into engage ment with said mandrel-bar.

(5. In apparatus for 'making seamless tubing, the combination with'rolls, of a mandrel-bar, a spherical plug adapted to engage said mandrel-bar, a guide' 'in front of said rolls, and a delivery device adapted to deposit the plug on said guide, whereby the tube will advance said plug intoengagement with said mandrel-bar.

7. In apparatus for making seamless tubing, the combination with rolls, of a mandrel-bar, a spherical plug adapted to engage said llltl]1(l1.l-l) 2l1', a guide in front of said rolls, a delivery device adapted to deposit the plug on said guide, a downwardly extended chute communicating with said guide, and means for delivering the plug passing down said chute back to said delivery device.

8. In apparatus for making seamless tubing, the combination with rolls, of a mandrel-bar, a spherical plug adapted to engage said mandrel-bar, a guide in front of said rolls, a rocking delivery device adapted to deposit the plug on said guide, a downwardlyextending chute communicating with said guide, an inclined trough communicating with said delivery device, means for delivering the plug from said chute into said trough, and means carried by said delivery device for closing the end of said trough adjacent said delivery device.

In testimony whereof I, the said MALcoLu U. Wursrnom, have hereunto set my hand.

MALCOLM U. WIKSTROM. 

